Antenna



FIG. 1 is a front elevation view of an antenna with a base in broken lines;

FIG. 2 is a side elevation view thereof;

FIG. 3 is a rear elevation thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a top perspective view thereof.

The broken lines are for illustration purposes only and form no part of the claimed invention. 

CLAIM The ornamental design for an antenna, as shown and described. 